Honorific question

I don’t actually study Japanese. I’m sure you must be pretty tired of people coming here asking questions because they’ve been watching anime so I apologize in advance. However, by watching anime, I picked up some common honorific and their usage (are at the least how they’re commonly used in fiction).

I was watching an anime and I keep hearing the use of a honorific that sounds like -ko/-kou (not sure on the vowels length) and gets subbed as “Lord”, but no matter how much I google, I can find no results, nor trying a reverse search by trying to find out what are the most used honorifics in this case, i only ever find “sama”, but Im sure thats not whats being said. It was used together with the Shogun’s given name, if that may help. I’d like if someone could identify the honorific and maybe explain what it means/how its different from “sama”, but even just giving me the Kanji would be enough, I’ll be happy to research more on my own.